The invention relates to exposure systems and more specifically to the use of multi-spot modulators, also known as light valves, in exposure systems. Currently used two dimensional light modulators have to be used without relative motion between the image of modulator and the exposed material. Any motion during imaging of a two dimensional array would blur the image in the direction of the motion. One solution is to use a linear array (such as in U.S. Pat. No. 4,571,603) however when imaging large area light sources such as incandescent or arc lamps onto a linear array there is a large loss of light. Another solution is to use high brightness, small area light sources such as lasers however this is expensive when large amounts of light are required at short wavelengths (blue and ultra-violet). This invention is of particular importance to processes requiring large amounts of modulated light in the blue and ultra-violet such as exposure of printing plates, exposure of printed circuit boards and stereolithography.